a. Field of the Invention
The present invention relates to lubricating oil pumps, and more particularly to a plunger type lubricating oil pump made to have the delivery controllable by taking two kinds of external conditions into consideration.
B. Description of the Prior Art
Various kinds of variable delivery type lubricating oil pumps performing a pumping action with a plunger reciprocated in the thrust direction with the rotation have been suggested and practiced today. However, in any of them, only one of such factors of controlling the delivery as the ambient temperature, atmospheric pressure, load applied to the engine and number of revolutions of the engine has been able to be introduced. Therefore, in case two or more of the above mentioned factors are simultaneously introduced by utilizing a conventional pump, as many pumps as the controlling factors to be introduced will have to be used simultaneously, much to the disadvantage in respect of the cost and space.